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1/* SPDX-License-Identifier: GPL-2.0-or-later */2/*3 * iSCSI over TCP/IP Data-Path lib4 *5 * Copyright (C) 2008 Mike Christie6 * Copyright (C) 2008 Red Hat, Inc. All rights reserved.7 * maintained by open-iscsi@googlegroups.com8 */9 10#ifndef LIBISCSI_TCP_H11#define LIBISCSI_TCP_H12 13#include <scsi/libiscsi.h>14 15struct iscsi_tcp_conn;16struct iscsi_segment;17struct sk_buff;18struct ahash_request;19 20typedef int iscsi_segment_done_fn_t(struct iscsi_tcp_conn *,21 struct iscsi_segment *);22 23struct iscsi_segment {24 unsigned char *data;25 unsigned int size;26 unsigned int copied;27 unsigned int total_size;28 unsigned int total_copied;29 30 struct ahash_request *hash;31 unsigned char padbuf[ISCSI_PAD_LEN];32 unsigned char recv_digest[ISCSI_DIGEST_SIZE];33 unsigned char digest[ISCSI_DIGEST_SIZE];34 unsigned int digest_len;35 36 struct scatterlist *sg;37 void *sg_mapped;38 unsigned int sg_offset;39 bool atomic_mapped;40 41 iscsi_segment_done_fn_t *done;42};43 44/* Socket connection receive helper */45struct iscsi_tcp_recv {46 struct iscsi_hdr *hdr;47 struct iscsi_segment segment;48 49 /* Allocate buffer for BHS + AHS */50 uint32_t hdr_buf[64];51 52 /* copied and flipped values */53 int datalen;54};55 56struct iscsi_tcp_conn {57 struct iscsi_conn *iscsi_conn;58 void *dd_data;59 int stop_stage; /* conn_stop() flag: *60 * stop to recover, *61 * stop to terminate */62 /* control data */63 struct iscsi_tcp_recv in; /* TCP receive context */64 /* CRC32C (Rx) LLD should set this is they do not offload */65 struct ahash_request *rx_hash;66};67 68struct iscsi_tcp_task {69 uint32_t exp_datasn; /* expected target's R2TSN/DataSN */70 int data_offset;71 struct iscsi_r2t_info *r2t; /* in progress solict R2T */72 struct iscsi_pool r2tpool;73 struct kfifo r2tqueue;74 void *dd_data;75 spinlock_t pool2queue;76 spinlock_t queue2pool;77};78 79enum {80 ISCSI_TCP_SEGMENT_DONE, /* curr seg has been processed */81 ISCSI_TCP_SKB_DONE, /* skb is out of data */82 ISCSI_TCP_CONN_ERR, /* iscsi layer has fired a conn err */83 ISCSI_TCP_SUSPENDED, /* conn is suspended */84};85 86extern void iscsi_tcp_hdr_recv_prep(struct iscsi_tcp_conn *tcp_conn);87extern int iscsi_tcp_recv_skb(struct iscsi_conn *conn, struct sk_buff *skb,88 unsigned int offset, bool offloaded, int *status);89extern void iscsi_tcp_cleanup_task(struct iscsi_task *task);90extern int iscsi_tcp_task_init(struct iscsi_task *task);91extern int iscsi_tcp_task_xmit(struct iscsi_task *task);92 93/* segment helpers */94extern int iscsi_tcp_recv_segment_is_hdr(struct iscsi_tcp_conn *tcp_conn);95extern int iscsi_tcp_segment_done(struct iscsi_tcp_conn *tcp_conn,96 struct iscsi_segment *segment, int recv,97 unsigned copied);98extern void iscsi_tcp_segment_unmap(struct iscsi_segment *segment);99 100extern void iscsi_segment_init_linear(struct iscsi_segment *segment,101 void *data, size_t size,102 iscsi_segment_done_fn_t *done,103 struct ahash_request *hash);104extern int105iscsi_segment_seek_sg(struct iscsi_segment *segment,106 struct scatterlist *sg_list, unsigned int sg_count,107 unsigned int offset, size_t size,108 iscsi_segment_done_fn_t *done,109 struct ahash_request *hash);110 111/* digest helpers */112extern void iscsi_tcp_dgst_header(struct ahash_request *hash, const void *hdr,113 size_t hdrlen,114 unsigned char digest[ISCSI_DIGEST_SIZE]);115extern struct iscsi_cls_conn *116iscsi_tcp_conn_setup(struct iscsi_cls_session *cls_session, int dd_data_size,117 uint32_t conn_idx);118extern void iscsi_tcp_conn_teardown(struct iscsi_cls_conn *cls_conn);119 120/* misc helpers */121extern int iscsi_tcp_r2tpool_alloc(struct iscsi_session *session);122extern void iscsi_tcp_r2tpool_free(struct iscsi_session *session);123extern int iscsi_tcp_set_max_r2t(struct iscsi_conn *conn, char *buf);124extern void iscsi_tcp_conn_get_stats(struct iscsi_cls_conn *cls_conn,125 struct iscsi_stats *stats);126#endif /* LIBISCSI_TCP_H */127